This invention relates to a single lever control whereby multiple control devices, such as hydraulic valves employed in directing machinery functions, are actuated separately or conjointly by movements of a single control lever. More specifically the invention finds application in backhoe earth working equipment where the array of hydraulic control valves, operable to carry out the various functions of the backhoe, are utilized by actuating a multiple of the valves by means of a single control lever.
Characteristically, in providing hydraulic controls for machinery movements, such as required in carrying out the digging operations with a backhoe, a single valve having its own control lever associated therewith is employed for each backhoe component movement to be carried out. Thus a line up of the valves, each with its own control handle, requires the operator to move to and from the individual valve control levers to carry out the desired motions in the backhoe digging operation. With the complexity of the movements involved in performing the multiple earth working functions it is particularly desired by some operators to have a single lever associated with a plurality of hydraulic valves so that by movements of this single lever the plurality of hydraulic valves are actuated either separately or conjointly. By this approach, individual or compound movements of the backhoe digging bucket, dipper, boom and swing of the backhoe relative to the supporting vehicle can be most expeditiously carried out by the operator's manipulation of a single lever for multiple valves rather than having the necessity of manipulating many individual levers, each associated with a single valve.
There have been proposals in the prior art to provide mechanisms whereby a single control lever is operable through its movements to actuate a pair of hydraulic valves connected in hydraulic fluid circuits to manipulate machinery components so that multiple control functions are performed by use of the single lever. Examples of such single lever controls to manipulate a plurality of hydraulic control valves appear in the U.S. Pat. Nos. to Miller, 3,388,609; Schwerdtfeger, 3,741,031; Campbell, 3,768,328; and Comer, 3,831,633. However, these single lever control mechanisms of the prior art involve mechanisms that are not only fairly complex and cumbersome but also employ completely separate assemblies of parts in addition to and for connection with the conventional individual hydraulic valves which are to be actuated.